benfulcher/hctsa

Multivariate TS classification

zeisal opened this issue · 3 comments

Dear Ben,
first of all thank you for all the work and effort you put into the hctsa package. It has been really helpful so far!

In the beginning I was dealing with a single sensor to monitor a pressure ts. The classification is mostly a 2-class but can also be a multiple class problem.
Now, I have multiple sensors available that monitor one and the same process. I would like to include possible relations and dependencies between the sampled variables into my analsis. Therefore, I like to ask if you have made any experience yet on how to implement a multivariate ts analysis in a smart way, still using all the beautiful functions within this package.

Thank you in advance and best regards,
Alex

Thanks Alex for the kind words and glad you're enjoying hctsa 😄
hctsa is designed for univariate time-series analysis, so there is no native support for the types of multivariate analyses your mention.
You have some options:

  1. Append lots of univariate feature matrices together (so that features of each univariate time series are captured). [you may wish to do some dimensionality reduction in this case]
  2. Add some features of multivariate dependencies manually.
    Neither of these options are natively supported at this stage, but you could use hctsa simply as a way to compute the feature matrix, that you then analyze yourself externally.

Hope this helps,
Ben

Thank you Ben for your quick reply.
I thought about the same. Since I used the reduced feature set of only ~220 features I still have an overseeable matrix even with multiple ts.
I also came across the question on why you selected especially those features for the reduced set. Is this from your experience or how did you select them?
Best regards, Alex

Hi Alex,
The reduced feature set of 220 is very rough and outdated.
See here for an updated pipeline on this topic (and associated paper).
Best,
Ben